Seminar

Postdoc day, Seminar 3: Diagonals of polytopes and higher structures

Higher algebraic structures in algebra, topology and geometry

25 February 15:10 - 15:40

Guillaume Laplante-Anfossi - University Paris 13

The set-theoretic diagonal of a polytope has the crippling defect of not being cellular: its image is not a union of cells. One is thus looking for a cellular approximation to the diagonal. Finding such an approximation in the case of the simplices and the cubes is of fundamental importance in algebraic topology: it allows one to define the cup product in cohomology. I will present a general method, coming from the theory of fiber polytopes of Billera and Sturmfels, which permits to solve this problem for any family of polytopes. I will then sketch how this machinery, applied to new families of polytopes, gives us the tools to define higher algebraic objects such as the tensor product of homotopy operads or a functorial tensor product of A-infinity categories.

 

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Organizers
Gregory Arone
Stockholm University
Tilman Bauer
KTH Royal Institute of Technology
Alexander Berglund
Stockholm University
Søren Galatius
University of Copenhagen
Jesper Grodal,
University of Copenhagen
Thomas Kragh
Uppsala University

Program
Contact

Alexander Berglund

alexb@math.su.se

Søren Galatius

galatius@math.ku.dk

Thomas Kragh

thomas.kragh@math.uu.se

Other
information

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